Spacecraft often use one or more solar panels, referred to in the plural hereinafter, to generate electricity for operation of electrical portions of the spacecraft. Systems depending upon electrical power include communication systems, payload, attitude control systems, and propulsion systems. The orbit of a spacecraft may be such as to require the solar panels to rotate relative to the body of the spacecraft, in order to track the sun. The position of the panels may need to be adjusted after an attitude or other control maneuver, so it is convenient to be able to move the panels in "forward" and "reverse" rotational directions at various speeds. Also, the position of the panels may have to be changed continuously during normal operation of the spacecraft, as the orbital position of the spacecraft relative to the sun changes.
When an adjustment of the position of the solar panels is required, a motor is energized, or the rotation rate of a motor is changed, to drive the panels relative to the body of the spacecraft. The motion or change of constant motion may cause unwanted vibrations of portions of the spacecraft to occur, and it also results in a tendency to change the attitude of the body of the spacecraft, which tendency may be corrected by an attitude control system, if one is provided. The vibrations may be damped by an actuator coupled to sense the vibration motion, as described, for example, in allowed U.S. patent application Ser. No. 08/031,252, filed Mar. 12, 1993 in the name of Stetson. While movable solar panels are described, any movable appendage tends to cause vibration and attitude error.
A simplified vibration or attitude error suppression arrangement for use in conjunction with solar panels and other movable appendages is desired.